Compressed air engine

ABSTRACT

Compressed air engine having an auxiliary air compressor for building up to a minimum a predetermined air pressure in a compressed air supply tank which feeds air through an engine RPM control valve for the engine pistons. Upon reaching the minimum air pressure, the electric motor is cut off and the auxiliary compressor is simultaneously engaged with the crankshaft to continue to build up to a maximum predetermined air pressure level and maintain this level for operation of the engine. A main recycle air compressor is provided for recycling. The multicylinder four-cycle combustion engine motor block may be converted into a four-cycle compressor for the system, and hydraulic means may also be used as a force-multiplying means for operation of the crankshaft.

United States ateiit [191 111 3,765,180

Brown Oct. 16, 1973 [54] COMPRESSED AIR ENGINE 3,563,032 2/1971 LaPointe 60/51 76 I ventor: RussellR.B wn 215 L fa tt St., 1 n Harrisburg,1,7109 a ye 6 Primary Examiner-Edgar W. Geoghegan 3 Attorney-Lawrence R.Radanovic [22] Filed: Aug. 1972 [21] Appl. No.: 277,629 [57] ABSTRACTRelated Appncafion Data Compressed air engine having an auxiliary aircompressor for building up to a minimum a predetermined [63] fga sggfgagof H3914 air pressure in a compressed air supply tank which feeds airthrough an engine RPM control valve for the 52 us. Cl 60/370, 60/374,60/415, mine Pismns' P Pi 91/4 sure, the electric motor 18 cut off andthe auxiliary [51] Int Cl F15, 11/06 Flsb 3/00 compressor issimultaneously engaged with the crank- [58] Fieid 60/53] R 62 51 shaftto continue to build up to a maximum predeter- 374 1 mined air pressurelevel and maintain this level for operation of the engine. A mainrecycle air compressor [56] References cued is provided for recycling.The multi-cylinder fourcycle combustion engine motor block may be con-UNlTED STATES PATENTS verted into a four-cycle compressor for thesystem, 859,235 7/1907 MacFarren 60/62 X and hydraulic means may also beused as a fo ce g z 223 multiplying means for operation of thecrankshaft. ur 2,100,445 Ill 1937 Le Bleu 60/52 HE X 9 Claims, 5 DrawingFigures B 14 'n sa HEATER 68 ll 3 l0) h" AUXlLlARY COMPRESSED NR NRSUPPLY COMPRESSOR l8 l 63'\ I 57 1 59 v- VOLTAGE marmmoa REGULATOR lOS\Ol 19 HEATER 54 v 3 42 c I01 0 v 44 9 VACUUM EXHAUST TANK MMN RECYCLECOMPRESSOR TO AUX.

PAIENIEDBCI 1 61m 3.765.180

sum 3 [1F 4 COMPRESSED SUPPLY TANK TO ALTER- NATO HEATER MNN RECYCLEYcompraessoxz.

VACUUM gxmusw TANK RCOMPRESSED AIR' ENGINE This application isacontinuation-in-part of my copending application, Serfl'No. 1 13,014filed Feb. 5, 1971, and now abandoned.

This invention relates generally to compressed air engines and moreparticularly to such an engine capable of maintaining the pressure 'inits supply tank at a predetermined: level for efficient and continuousoperation.

Internal combustion engines for powering motor vehicles andfossil-burning plants used in energy producingoperations 1 throughoutthe industry, have been under attack for many years because of theirinherent characteristics which produce air and other pollutants. Stepshave been therefore taken to increase the combustion efficiency andfilter the exhaust from these power plants with a view to saving" theatmosphere through more efficient and. cleaner burning. The relativesuccess of such operations has, however, been slow and limited becauseof the many problems which arise. One of theapproaches taken in theproduction of a completely clean power plant is the design of the airengine which is, of. course, completely clean since there are absolutelyno combustion gasses-to contend with. However, design in this arealhasbeen somewhat limited because of the reduced power output capable forsuch engines and because of their somewhat inefficient and complexoperation. The air engine has therefore been used in some casesasanauxiliary power plant with a combustion engineor it has been abandonedin favor of other systems becauseof the auxiliary powerneeded'to'maintain adequate supply of air pressure for the system.

A compressed air enginehas been therefore devised which avoids all thesedrawbacks byamaking use of an auxiliary air compressor started byanelectric motor for maintaining a predetermined minimum operatingpressure level necessary'forthe system by simple, efficient andinexpensive-means, thevelectric motor being shut off when thisminimumlevel is reached. This is the principal object of the presentinvention.

Another object of this invention isto provide such an air engine whichmakes use of an auxiliary air compressor having two electric clutchmeans thereon, one

A still further object of this invention is to provide such an airengine which additionally makes use of hydraulic means as aforce-multiplying factor in operating the pistons for increasedefficiency.

Other objects, advantages and novel features of the invention willbecome apparent when the following detailed description of the inventionis considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic view showing the various parts of the compressedair engine in accordance with the present invention;

FIG. 2 is a top plan view, partly broken away, of an engine blockconverted into a four-cycle air compressor;

FIG. 3 is a sectional view taken substantially along the line of 33 ofFIG. 2 showing a typical crosssection of the conversion head and a partof one of the cylinders;

FIG. 4 is a schematic view showing another embodiment of a compressedair engine in accordance with the present invention; and

FIG. 5 is a schematic view of still another embodiment of a compressedair engine of the invention.

Turning now to the drawings wherein like reference characters refer tolike and corresponding parts throughout the several views, there isshown in FIG. 1 a schematic view of an air engine as having a compressedair supply tank 10 into which compressed air is fed up to apredetermined minimum pressure level by an auxiliary air compressor 11.Compressor 11 is powered by an electric motor 12 which, when energized,rotates drive shaft 13 of the compressor through pulleys 14, belt 15 anda first electric clutch 16. This clutch may be of a type which, whenenergized, is engaged.

To energizemotor 12, an electric switch 17 is actuated which closes theelectric circuit for clutch 16 through a closed electric pressurecontrol switch 25, therebyenergizing the clutch for engagement and forclosing an electromechanical motor switch 18. Operation of the electricmotor 12 and engagement of first through which the auxiliary compressoris driven to fill 1 takes over through which the auxiliary compressor.is again driven for rechargingthe compressed air supply tank to continueto build up to a maximum predetermined air pressure level and tomaintain this level for smooth operation.

A further object of the present invention is to provide such an airengine wherein a main recycle compressor is also made use of forrecycling compressed air throughout the system, this recycle compressortaking in air either from the outside for its operation or from a vacuumexhaust tank into which air from the last of the engine pistonsexhausts.

A still further object of this invention is to provide such a compressedair engine which makes use of a multicylinder four-cycle engineconverted into a fourcycle compressor used in the system, twin camshafts being used in a conversion head and being properly timed for theintake and exhaust ports of each cylinder.

electric clutch l6 drives shaft 13 thereby causing com pressed air to bepumped from auxiliary compressor 11 through air line 23 and into thecompressed air supply tank 10. The compressed air may be heated to apredetermined level by means of a coiled heater 24 for purposes ofexpansion. The compressed air in tank 10 passes through air line 22 andinto control switch 25 which remains closed until the pressure builds upto a minimum predetermined level set for minimum operation of the airengine. This switch is designed as having a pressure diaphragm 26 on acontact arm 20 for movement between contact points 103 and 1104. Beforethe minimum predetermined pressure level is reached, a coil spring 27maintains arm 20 in contact with 103 whereupon clutch 16 remainsenergized. The spring force of spring 27 is such as will be overcome bythe pressure reaching its predetermined minimum as to cause arm 20 tocontact 104. At such time, the circuit to clutch 16 is broken andaccordingly clutch 16 is disengaged whereupon motor 12 is stopped. Inthe meantime the engine may be caused to idle by the operator at hisdiscretion by closing an electric switch 19 which serves to open asolenoid valve 21 on tank 10 and another solenoid valve 105 in air line311 to permit air to by-pass a main control valve 102 thereby allowingthe engine to operate at idling speed. A needle valve 101 is providedfor adjusting the idle through valve 105.

When motor 12 is stopped, auxiliary air compressor 11 of course alsostops. While arm is in contact with point 104 at the minimumpredetermined pressure level, the circuit to a second electric pressurecontrol switch 65 is closed through an arm 60 to thereby energize asecond electric clutch 68 on drive shaft 13 of compressor 11. Switch 65is similar to switch in that it includes a diaphragm plate 66 having acontact arm 60 normally maintained in contact with a contact point 106by means of a coil spring 67. The force of this spring is such that itwill not be overcome by the minimum air pressure level but cause thecircuit to remain closed until an increased maximum predeterminedpressure level is attained. At such time, arm 60 is moved against spring67 away from contact 106 thereby breaking the circuit and disengagingclutch 68 for stopping compressor 11. Also, as the maximum pressurelevel drops slightly, clutch 68 will be again engaged since arm 60 willagain contact point 106. Compressor 11 will therefore again be turned onto replenish this loss during engine operation.

Compressed air is fed through line 28 and into a coiled heater 29,through line 31 and into the intake port 32 ofa first engine pistoncylinder 33. Intake valve 34 is designed as being closed when piston 35of the first cylinder is in its lowermost down stroke as shown. Piston35 is connected to a crankshaft 36 as is intake valve 34 and an exhaustvalve 37, each of which being operable for opening and closing therespective intake and exhaust ports in a conventional manner as by camlifters as the crankshaft rotates. Air line 38 connects the exhaust port39'of piston cylinder 33 with the intake port 40 of a second pistoncylinder 42 so that, upon the upward stroke of piston 35, compressed airis fed through air line 38 and into second piston cylinder 42 at whichtime intake valve 43 is opened and exhaust valve 44 is closed, boththese valves being connected to crankshaft 36 in a normal manner foropening and closing their respective intake and exhaust ports 40 and 41via their respective cam lifters from the crankshaft. Upon the upwardstroke of piston 45, compressed air is fed through open exhaust port 41and air line 46 and into a vacuum exhaust tank 47. A drain plug or valve48 is provided for tank 47 and a maximum vacuum relief valve 49 is alsoprovided in the event it becomes necessary to vent tank 47. Compressedairis then fed through air line 51, which may be heated for expansion bya coiled heater 52, and is fed into a main recycle air compressor 53. Amaximum air pressure control valve 54 is provided thereon, and thecompressor is operatively connected with crankshaft 36 through pulleys55 and belt 56. An alternator 57 and a voltage regulator 58 are alsooperatively connected to crankshaft 36 by means of pulleys 59 and belt61. Moreover, driveshaft 13 of the auxiliary air compressor 11 isoperatively connected with crankshaft 36 via pulleys 62 and a belt 63.

When the air engine is put into operation and clutch 68 is engaged,compressor 1 l is belt driven from crankshaft 36 and continues operationto attain the predetermined maximum air pressure and thereafter,intermittently or at frequent intervals, as controlled by switch 65, toreplenish any slight losses during engine operation. However, each timethe air pressure drops below the predetermined minimum operating level,motor 12 is automatically turned on through pressure control switch 25as the arm 20 thereof contacts contact point 103 under the action ofspring 27. The electric circuit to clutch 16 is then closed and, in themanner as aforedescribed, compressor 11 is turned on through operationof motor 12 to build the pressure back up to the predetermined minimumoperating level.

Turning to FIG. 2 of the drawings, a six-cylinder fourcycle enginereplacement conversion head 73 which, when adapted to a standard engineblock 69, permits it to remain as a four-cycle power stroke and afourcycle air compressor, or an air engine one-half of the time and anair compressor one-half of the time. This standard engine block is shownas having six cylinder bores I to VI usable in place of the two-cyclecylinders 33 and 42 in the system as described above with reference toFIG. 1. As will be seen, the FIG. 2 arrangement acts as a four-cycle aircompressor or an air engine onehalf the time and as an air compressorone-half the time thereby eliminating the need for compressor 53. Twostandard four-cycle cam shafts 71, 72, properly timed, are provided withrespective eccentric cam lobes 76, 77 and 79, 82. Each cam shaft 71 and72 is operatively connected with crankshaft 36 in timed relation sothat, for example, shaft 71 is in phase therewith and shaft 72 is out ofphase. Each of the lobes 76 is associated with respective intake ports athrough 75f, lobes 77 are each associated with respective exhaust ports780 through 78f, lobes 82 are each associated with respective intakeports 81a through 8lfand lobes 79 are each associated with respectiveexhaust ports 83a through 83f. These lobes are each designed for propertiming so that port 81a is open at the top of the power stroke for thepiston (not shown) of bore I while the remaining three ports 83a, 75aand 78a are closed during travel of the piston from top to bottom. Atthe bottom of the power stroke, 810 closes and 83a opens along with 81ballowing exhaust from cylinder I to the next cylinder II in seriesorder. When the piston in bore 1 travels from bottom to the top of itscylinder, port 830 closes and, simultaneously, 75a opens and remainsopen as the piston travels from top to bottom of its compression strokepulling the vacuum from the vacuum exhaust tank 47 or from the outside.At the bottom of the compression stroke ports 75a, 81a, 83a are closedand ports 78a opens to exhaust air past a baffle valve 51a and throughexhaust manifold 64 to the compressed air supply tank 10. When port 81bis open (as aforedescribed) the piston in cylinder bore II operates inthe same manner as the piston described above in cylinder bore I, and soon for cylinder bores II to VI in series order. For cylinder VI, theexhaust from the power stroke, however, is exhausted into the vacuumexhaust tank 47 from which the pistons of all cylinders pull in outsideair or from the vacuum exhaust tank for the intake of the compressionstroke.

FIG. 3 is a typical cross-sectional view through the block 69 andconversion head 73 showing only ports 78d and 83d and baffle valve 51d,it being understood that ports 75d and 81d of cylinder IV are similar inall respects to the ports shown herein but are omitted for purposes ofclarity. The remaining cylinders are similarly designed for operation inaccordance with the above description.

In the FIG. 2 embodiment, crankshaft 36 is not shown although it isoperatively interconnected as in FIG. 1 to each of the six piston rods.The air engine as described in FIG. 1 is otherwise the same except thatthe four-cycle six cylinder engine of FIG. 2 is used instead of thetwo-cycle two cylinder 33, 42 arrangement of FIG. 1 in conjunction withcompressor 53.

Another embodiment of the invention is shown in FIG. 4 of the drawingswhich schematically sets forth thedifferent characteristics of thisembodiment as compared to that of FIG. 1. Accordingly, those identicalelements including the compressed air supply tank, the electric motor,the auxiliary air compressor and the two electric pressure controlswitches are not shown and similar elements of FIG. I bear the samereference numerals in this Figure.

Instead of piston cylinders 33 and 42 being serially connected as theyare in FIG. 1, they are connected in parallel in FIG. 4 so thatcompressed air through line 28 is fed through lines 28a and 28b intorespective intake ports 86 and 87 of the two piston cylinders. Theintake and exhaust valves 34, 43 and 37, 44, respectively, for each ofthe piston cylinders are operatively connected to crankshaft 36 in thecustomary manner for opening and closing their respective intake ports86, 87 and exhaust ports 88, 89 as push rods 106, 107 and 106, 107' arealternately lifted by rotation of their respective cam lobes duringcrankshaft rotation.

Compressed air through air lines 28a and 28b is fed through the open oneof intake ports 86, 87 and to the top of hydraulic cylinder 91, 92, eachof which has a floating piston 93, 94, respectively, therein. Thefloating piston, for example, 94, as shown in FIG. 4, is pusheddownwardly which in turn feeds hydraulic fluid through a fluid line 96to the top of piston cylinder 42 thereby causing piston 45 to be moveddownardly. Piston of cylinder 33 is correspondingly moved upwardly bythe crankshaft rotation so as to feed hydraulic fluid through its fluidline 95 and back into cylinder 91 thereby elevating floating piston 93and forcing the compressed air through its line 97 and'through theexhaust port 88 into air line 46 and into vacuum exhaust tank 47 (or tothe outside). Floating piston 93 is moved downwardly and floating piston94 upwardly in reverse order for that described above upon continuedcrankshaft rotation. The pressure created in the fluid by a small forceacting on floating pistons 93 and 94 in their respective cylindersresults in a large force'on the respective large pistons 34 and 35,thereby effecting a more efficient rotation of crankshaft 36.

The FIG. 1 embodiment may be easily modified to include the hydraulicmeans as disclosed in FIG. 4 with the use of appropriate plates andgaskets embodying a fluid line 96 and air line 98 for piston cylinder42, and similar gaskets and plates embodying a fluid line 95 and airline 97 for piston cylinder 33 for diverting the air flow to thehydraulic cylinders instead of directly to piston cylinders 33, 42 as inFIG. 1.

Another embodiment, shown in FIG. 5, demonstrates another type ofmechanical advantage developed for the engine pistons, except that thefloating pistons of FIG. 4 are eliminated and sealed piston cylinders108, 108' are each instead connected directly with each piston 35 and 45located within respective cylinders 33 and 42. Those pistons may be ofany desired shape since no rings are needed. Only a wrist pin action (asshown) is designed between the piston and its rod, and a crank actionoccurs between its rod and the crankshaft. Accordingly, cylinders 33 and42 respectively act as guides for pistons 35 and 45. Rods 109, 109' ofpistons 110, 110 in each cylinder 108, 108' are connected to each oftheir respective pistons 35 and 45.

As in FIG. 4, rods 106, 106 and 107, 107' are each extended throughrespective cylinder head plates 111, 111 with each of these rods beingin contact with a respective button type air valve 112, 112' as shown.These air valves are each of a conventional design so that, upon upwardmovement of their respective buttons 114, 114' and 115, 115, air ispermitted to flow therethrough.

Intake ports 86, 87 and exhaust ports 88, 89 are respectively located inair valves 1112, 112'.

Compressed air through air lines 280 and 28b (not shown in FIG. 5 forclarity) is fed through the open one of intake ports 86, 87 in valves1E2, 112' and to the top of pistons 118, 1110 through air lines 91, 98as one of respective rods 106, 106' is lifted by rotation of its camlobe during crankshaft rotation. Assuming piston 110' is thereby pusheddownwardly, piston 45 is also caused to be moved downwardly. Piston 35of cylinder 33 is correspondingly, moved upwardly by crankshaft rotationat which time its exhaust port 88 is open and its intake port 86 closedby movement of rods 107 and 1106 during crankshaft rotation. At the topthe stroke of piston 110, port 86 opens and port 88 closes, with thereverse for ports 87 and 89, so that downward stroke of piston 110 maybe effected in the same manner as described for cylinder 108.

It should be understood that the engine in accordance with the FIG. 5 isthe same as that of FIGS. 1 and 4except for those differences asaforedescribed. Accordingly, compressors 11 and 53, switches 25 and 65,tanks 10 and 47, motor 12 and the various air and electricalinterconnections are also used for the FIG. 5 embodiment but are notshown for purposes of clarity.

In view of the foregoing, it can be seen that a simple, efficient andhighly effective compressed air engine has been devised which makes useof an electric motor for starting an auxiliary air compressor forpressurizing a compressed air supply tank which, after a minimumpredetermined pressure level is reached, commences operation of pistoncylinders for rotation of a crankshaft. The electric motor is stopped assoon as this minimum predetermined pressure level is reached after whichthe auxiliary air compressor continues operation from the crankshaft bymeans of pressure control switches which serve to first de-energize oneelectric clutch and thereafter energize another electric clutchconnected to the compressor. Hydraulic means may be used to increase themoving force on the pistons to effect a more efficient crankshaftrotation, and a conversion head is made use of in converting a standardmulticylinder four-cycle engine block into a fourcycle air engine and afour-cycle air compressor for the air engine.

Obviously, many modifications and variations of the present inventionare possible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. A compressed air engine having engine pistons for rotation of acrankshaft, the engine being characterized by a compressed air supplytank connected with an auxiliary air compressor, first electric clutchmeans on said air compressor, a switch operated electric motoroperatively connected with said air compressor, a first electricpressure control switch connected with said clutch means, an electricswitch for energizing said clutch and the switch of said electric motorthereby actuating said motor for driving said compressor through saidfirst clutch, said tank being connected with said engine pistons inseries, means for operating said pistons from said tank after apredetermined minimum air pressure level is reached, a main recycle aircompressor interconnected between the last of said series connectedpistons and said supply tank for recycling compressed air through theengine, a second electric clutch means on said auxiliary air compressor,and a second electric pressure control switch connected with said secondclutch means, said auxiliary air compressor being operatively connectedwith said crankshaft, said first electric pressure control switch beingso arranged as to open to thereby de-energize said first clutch and stopsaid motor when the pressure in said tank reaches the minimumpredetermined operating air level, said second electric pressure controlswitch being so arranged as to be closed to thereby energize said secondclutch at the time said first clutch is de-energized maintainingoperation of said auxiliary air compressor from the crankshaft up to amaximum predetermined operating air pressure level, and again startingsaid auxiliary air compressor when the pressure in said tank falls belowsaid maximum predetermined operating air level.

2. The engine according to claim 1 wherein said main recycle aircompressor is operatively connected with said crankshaft.

3. The engine according to claim 1 wherein a vacuum exhaust tank isprovided into which said last piston exhausts and from which air is fedinto said main recycle air compressor.

4. A compressed air engine having engine pistons for rotation of acrankshaft, the engine being characterized by a compressed air supplytank connected with an auxiliary air compressor, first electric clutchmeans on said air compressor, a first electric pressure control switchconnected with said clutch means, an electric switch for energizing saidclutch and the switch of said electric motor thereby actuating saidmotor for driving said compressor through said first clutch, said tankbeing connected with said engine pistons in series, means for operatingsaid pistons from said tank after a predetermined minimum air pressurelevel is reached, a second electric clutch means on said auxiliarycompressor, and a second electric pressure control switch connected withsaid second clutch means, said com-- pressor being operatively connectedwith said crankshaft, said first electric pressure control switch beingso arranged as to open to thereby de-energized said first clutch andstop said motor when the pressure in said tank reaches the minimumpredetermined operating air level, said second electric pressure controlswitch being so arranged as to be closed to thereby energize said secondclutch at the time said first clutch is de-energized maintainingoperation of said auxiliary air compressor from the crankshaft up to amaximum predetermined operating air pressure level and again startingsaid auxiliary air compressor when the pressure in said tank falls belowsaid maximum predetermined operating air level, said pistons comprisinga multi-cylinder fourcycle engine having intake and exhaust valves foreach power stroke thereof, intake and exhaust valves for eachcompression stroke thereof, and a baffle valve in the exhaust of thecompression stroke for each said cylinder, a camshaft for said powerstroke valves and another camshaft for said compression stroke valves,cam lobes on each said camshaft arranged to open and close said valvesduring the power and compression strokes in series order upon rotationof said camshaft.

5. A compressed air engine having engine pistons for rotation of acrankshaft, the engine being characterized by a compressed air supplytank connected with an auxiliary air compressor, first electric clutchmeans on said compressor, a switch operated electric motor operativelyconnected with said air compressor, a first electric pressure controlswitch connected with said clutch means, an electric switch forenergizing said clutch and the switch of said electric motor therebyactuating said motor for driving said compressor through said firstclutch, said tank being connected with said engine pistons in parallel,fluid means for operating said pistons from said tank after apredetermined minimum air pressure level is reached, means associatedwith each of said engine pistons for actuating said pistons, a mainrecycle air compressor interconnected between said parallely connectedpistons and said supply tank for recycling compressed air throughout theengine, a second electric clutch means on said auxiliary air compressor,and a second electric pressure control switch connected with said secondclutch means, said auxiliary air compressor being operatively connectedwith said crankshaft, said first electric pressure control switch beingso arranged as to open to thereby deenergize said first clutch and stopsaid motor when the pressure in said tank reaches the minimumpredetermined operating air level, said second electric pressure controlswitch being so arranged as to be closed to thereby energize said secondclutch at the time said first clutch is de-energized thereby maintainingoperation of said auxiliary air compressor when the pressure reaches aminimum predetermined level from the crankshaft up to a maximumpredetermined operating air pressure level and again starting saidauxiliary compressor when the pressure in said tank falls below saidmaximum predetermined operating air pressure level.

6. The engine according to claim 5 wherein said main recycle aircompressor is operatively connected with said crankshaft,

7. The engine according to claim 5 wherein a vacuum exhaust tank isprovided into which each of said pistons exhaust and from which air isfed into said main recycle air compressor.

8. The engine according to claim 5 wherein said fluid means comprises ahydraulic cylinder for each said piston at least partially filled withhydraulic fluid and having a floating piston therein for forcing thefluid from said hydraulic cylinder into its connected piston cylinderupon movement of said floating piston by the compressed air from thesupply tank.

9. The engine according to claim 5 wherein said fluid means comprises asealed air cylinder having a piston therein connected to each saidengine piston which acts as a guide for its respective air cylinderpiston, the downward movement of the power stroke of each said enginepiston being actuated by its respective air cylinder piston.

i i i i

1. A compressed air engine having engine pistons for rotation of acrankshaft, the engine being characterized by a compressed air supplytank connected with an auxiliary air compressor, first electric clutchmeans on said air compressor, a switch operated electric motoroperatively connected with said air compressor, a first electricpressure control switch connected with said clutch means, an electricswitch for energizing said clutch and the switch of said electric motorthereby actuating said motor for driving said compressor through saidfirst clutch, said tank being connected with said engine pistons inseries, means for operating said pistons from said tank after apredetermined minimum air pressure level is reached, a main recycle aircompressor interconnected between the last of said series connectedpistons and said supply tank for recycling compressed air through theengine, a second electric clutch means on said auxiliary air compressor,and a second electric pressure control switch connected with said secondclutch means, said auxiliary air compressor being operatively connectedwith said crankshaft, said first electric pressure control switch beingso arranged as to open to thereby de-energize said first clutch and stopsaid motor when the pressure in said tank reaches the minimumpredetermined operating air level, said second electric pressure controlswitch being so arranged as to be closed to thereby energize said secondclutch at the time said first clutch is deenergized maintainingoperation of said auxiliary air compressor from the crankshaft up to amaximum predetermined operating air pressure level, and again startingsaid auxiliary air compressor when the pressure in said tank falls belowsaid maximum predetermined operating air level.
 2. The engine accordingto claim 1 wherein said main recycle air compressor is operativelyconnected with said crankshaft.
 3. The engine according to claim 1wherein a vacuum exhaUst tank is provided into which said last pistonexhausts and from which air is fed into said main recycle aircompressor.
 4. A compressed air engine having engine pistons forrotation of a crankshaft, the engine being characterized by a compressedair supply tank connected with an auxiliary air compressor, firstelectric clutch means on said air compressor, a first electric pressurecontrol switch connected with said clutch means, an electric switch forenergizing said clutch and the switch of said electric motor therebyactuating said motor for driving said compressor through said firstclutch, said tank being connected with said engine pistons in series,means for operating said pistons from said tank after a predeterminedminimum air pressure level is reached, a second electric clutch means onsaid auxiliary compressor, and a second electric pressure control switchconnected with said second clutch means, said compressor beingoperatively connected with said crankshaft, said first electric pressurecontrol switch being so arranged as to open to thereby de-energized saidfirst clutch and stop said motor when the pressure in said tank reachesthe minimum predetermined operating air level, said second electricpressure control switch being so arranged as to be closed to therebyenergize said second clutch at the time said first clutch isde-energized maintaining operation of said auxiliary air compressor fromthe crankshaft up to a maximum predetermined operating air pressurelevel and again starting said auxiliary air compressor when the pressurein said tank falls below said maximum predetermined operating air level,said pistons comprising a multi-cylinder four-cycle engine having intakeand exhaust valves for each power stroke thereof, intake and exhaustvalves for each compression stroke thereof, and a baffle valve in theexhaust of the compression stroke for each said cylinder, a camshaft forsaid power stroke valves and another camshaft for said compressionstroke valves, cam lobes on each said camshaft arranged to open andclose said valves during the power and compression strokes in seriesorder upon rotation of said camshaft.
 5. A compressed air engine havingengine pistons for rotation of a crankshaft, the engine beingcharacterized by a compressed air supply tank connected with anauxiliary air compressor, first electric clutch means on saidcompressor, a switch operated electric motor operatively connected withsaid air compressor, a first electric pressure control switch connectedwith said clutch means, an electric switch for energizing said clutchand the switch of said electric motor thereby actuating said motor fordriving said compressor through said first clutch, said tank beingconnected with said engine pistons in parallel, fluid means foroperating said pistons from said tank after a predetermined minimum airpressure level is reached, means associated with each of said enginepistons for actuating said pistons, a main recycle air compressorinterconnected between said parallely connected pistons and said supplytank for recycling compressed air throughout the engine, a secondelectric clutch means on said auxiliary air compressor, and a secondelectric pressure control switch connected with said second clutchmeans, said auxiliary air compressor being operatively connected withsaid crankshaft, said first electric pressure control switch being soarranged as to open to thereby de-energize said first clutch and stopsaid motor when the pressure in said tank reaches the minimumpredetermined operating air level, said second electric pressure controlswitch being so arranged as to be closed to thereby energize said secondclutch at the time said first clutch is de-energized thereby maintainingoperation of said auxiliary air compressor when the pressure reaches aminimum predetermined level from the crankshaft up to a maximumpredetermined operating air pressure level and again starting saidauxiliary compressor when the pressure in said tank falls beloW saidmaximum predetermined operating air pressure level.
 6. The engineaccording to claim 5 wherein said main recycle air compressor isoperatively connected with said crankshaft.
 7. The engine according toclaim 5 wherein a vacuum exhaust tank is provided into which each ofsaid pistons exhaust and from which air is fed into said main recycleair compressor.
 8. The engine according to claim 5 wherein said fluidmeans comprises a hydraulic cylinder for each said piston at leastpartially filled with hydraulic fluid and having a floating pistontherein for forcing the fluid from said hydraulic cylinder into itsconnected piston cylinder upon movement of said floating piston by thecompressed air from the supply tank.
 9. The engine according to claim 5wherein said fluid means comprises a sealed air cylinder having a pistontherein connected to each said engine piston which acts as a guide forits respective air cylinder piston, the downward movement of the powerstroke of each said engine piston being actuated by its respective aircylinder piston.